Q420qD钢材应力腐蚀特征试验研究

为研究Q420qD钢材应力腐蚀特征,对应力水平为0.3倍屈服应力和无应力工况下共60个试件在相同腐蚀环境中进行通电加速腐蚀试验,建立了有应力和无应力腐蚀试件的腐蚀速率模型并进行对比。对部分腐蚀试件表面进行三维形貌扫描,研究了有应力和无应力试件的形貌发展规律、蚀坑深度分布规律以及蚀坑形态与径深比规律。利用差分盒维数计算腐蚀表面分形维数,对比了有应力和无应力试件分形维数随质量损失率和腐蚀时间的变化规律。结果表明:当试件应力为0.3倍屈服应力时,有应力和无应力试件腐蚀速率均表现为先快后慢,在目标腐蚀率小于18%时,有应力和无应力试件腐蚀速率近似为常数,且有应力试件的腐蚀速率近似为无应力试件的1.15倍; 有应力试件腐蚀形貌发展快于无应力试件,且最终腐蚀形态都以均匀腐蚀为主; 有应力和无应力试件表面分形维数变化规律相似,均在腐蚀初期迅速增大,之后出现减小—增大—减小的周期性上下波动现象; 有应力试件分形维数在腐蚀初期发展速率高于无应力试件,且有应力试件的分形维数普遍大于无应力试件; 蚀坑形态以球冠状为主,有应力和无应力试件单个蚀坑深度分布均能较好地服从正态分布规律; 蚀坑径深比变化范围稳定于2～6,平均值在4附近波动。     

NEIGHBORHOOD FORECLOSURES AND PROPERTY TAX BURDEN: AN EXAMINATION OF CHANGE IN VALUATION STANDARD AND ASSESSMENT EQUITY

The quality of property tax assessment practices impacts the stability of local government revenue and the equity of property tax burden. This study examines the potential shift in property tax burden associated with concentrations of foreclosures while taking into account a procedural transition from a lagged market versus a current market valuation standard. The findings suggest that property tax administration matters, especially with a growing number of foreclosures. In the case studied, current market value assessments partially mitigate equity consequences of nearby foreclosure sales. It is concluded that foreclosures have a relatively small but significant negative effect on the change in assessed values of nearby properties. That shift mitigates the over‐assessment associated with foreclosures under a lagged assessment standard. However, the analysis illuminates the continued complexity of achieving horizontal equity in the property tax base within or near higher concentrations of foreclosures after the transition to current market value assessment.     

浅谈设计企业分立业务的税收策划

近几年随着中国经济的快速发展,设计企业的发展越来越快且规模越来越大,为了更好更快的发展,很多设计企业选择了分立。为了降低分立所增加的税务成本,企业在分立时应结合分立前后的相关业务事项及相关税收优惠政策进行税收策划。本文针对设计企业是在分立时把房产投资给其分立的子企业还是以出租形式提供给子公司的税务成本及其晒图部门分立出去的税务成本进行了简单分析。     

A state personal income tax simulation model

A simple econometric model of a state personal income tax is presented. The model is designed for economies subject to rapid population increase by means of a double log specification of an average tax schedule. Various tests are presented to validate the model. It is then incorporated into a full econometric model and the revenue and general equilibrium effects of two types of tax cut are considered. It is found that changes in state personal income tax rate schedules and deduction provisions have significant general equilibrium effects on open economies and these result in substantial induced revenue impacts.     

Modeling the sorption kinetics of divalent metal ions to hematite

The sorption kinetics of the divalent metals Zn, Co, Ni, and Cd to hematite were studied in single sorbate systems with high sorbate/sorbent ratios (from 1.67 to 3.33mol sorbate/mol sorption sites) in 10mM Na-piperazine N,N'-bis 2-ethane sulfonic acid (Na-PIPES) solution at pH 6.8. The experimental data showed a rapid initial sorption (half-time about 1min) followed by slower sorption that continued for 1-5 days. The sequence of fast to slow sorption kinetics was modeled by slow inner-sphere (IS) complexation in equilibrium with outer-sphere (OS) complexes. Although the OS reaction was fast and considered to be in equilibrium, the extent of OS complexation changed over time due to increased surface potential from the IS complexes. For example, the model showed that the dimensionless OS complexation function, K(os), decreased from 0.014 initially to 0.0016 at steady state due to sorption of 4x10(-5)M Zn(II) to 2gL(-1) hematite. Sorption rate constants, k(ads), for the various divalent metals ranged from 6.1 to 82.5M(-1)s(-1). Desorption rate constants, k(des), ranged from 5.2x10(-7) to 6.7x10(-5)s(-1). This study suggests that the conversion from OS to IS complex was the rate-determining step for the sorption of divalent metals on crystalline adsorbents.     

房地产开发企业“甲供材”的会计处理及税务分析

近年来,随着房地产行业的迅速发展,越来越多的企业认识到合同管理与成本控制的重要性。为了降低成本,确保工程质量,大多数企业在施工合同中采用了"甲供材"的方式。由于"甲供材"方式的日益复杂化,税务部门对"甲供材"的征收管理难度也逐步加大。本文首先阐述了"甲供材"存在的原因、分析其现状,然后介绍了"甲供材"的相关税收政策、会计核算方式并对其税务处理进行了分析,最后得出结论并提出一些建议。     

Differential assessment and state land use controls in Hawaii

Discussion of Hawaii's experience suggests both advantages and difficulties in establishing complementary relationships between differential agricultural assessment and statewide land use controls. In Hawaii, as elsewhere, differential assessment was guided by traditional rent theory with valuations increasing progressively with higher quality lands. Actual practice indicated conservation purposes were better served by a more regressive structure. This suggests a restructuring of assessment rates for states which continue to rely on this method for farmlands preservation purposes, assuming distributional equity issues are dealt with.Mr. Okimoto is presently economist with the Hawaii State Department of Transportation, USA.     

穿越——快慢成都

今天的成都正努力变得更快捷、更高效、更庞大,过去人们津津乐道的"慢成都"正成为"快成都",过去成都人习惯的"小生活"正在变成"大生活"。作者选择成都的东、西两点"穿越"城市来发现和解读这个城市的当下,通过城市剖面来揭示成都的慢生活与快节奏并存,藉由对城市快慢的体验,针对"现代田园城市"提出对城市加速发展和城市记忆消减的反思命题。     

考虑层间效应的钢纤维混凝土隧道单层衬砌#br# 受力特征模型试验研究

为探究考虑层间接触效应的钢纤维混凝土隧道单层衬砌内力分布规律,自行设计考虑层间效应的单层衬砌模型并研制竖向油压5MPa和侧向压力1.5MPa作为逐级施加的卧式加载试验台架,开展不同荷载作用下的钢纤维混凝土隧道单层衬砌受力特征模型试验。研究结果表明：不考虑层间接触特征的单层衬砌与考虑接触特征的单层衬砌在拱腰和墙角处的安全系数均为最低,最容易出现弯矩和轴力突变;考虑层间接触特征的单层衬砌最大弯矩与最大轴力均出现在拱脚处,层间接触面存在明显黏结力,结构的轴力增加和弯矩减小,内力变得均衡,结构的整体安全性高于不考虑层间接触面,相对不考虑层间效应,受力最不利的左右拱脚处的安全系数分别增加143.7%、149.4%;当竖向油压达到3MPa、侧向油压值达到0.9MPa时,仰拱周围层间接触面压力增长速度显著加快,仰拱处混凝土由线弹性转变为塑性,竖向油压达到4MPa,侧向油压值达到1.2MPa时,仰拱、拱角与拱顶层间接触面应力值有减小或反向增长的趋势,仰拱、墙角等界面发生破坏;钢纤维在单层衬砌裂缝扩展在30%~70%之间阻裂效果最好。     

Simulation of the impact of financial incentives on solar energy utilization for space conditioning and water heating: 1985

Financial incentives designed to accelerate the use of solar energy for heating, cooling, and water heating of buildings have been proposed by both state and federal legislative bodies in the U.S.A. Among the most frequently mentioned incentives are sales and property tax exemptions, tax deductions and credits, rapid amortization provisions, and interest rate subsidies. At the present time there is little available information regarding the ability of such incentives to advance the rate of solar energy utilization. This paper describes the derivation and use of a computer simulation model designed to estimate solar energy use for space conditioning and water heating for given economic, climatic, and technological conditions. When applied to data from the Denver, Colorado metropolitan area, the simulation model predicts that sales tax exemptions would have little impact over the next decade, interest rate subsidies could more than double solar energy use, and the other proposed incentives would have an intermediate impact.     

水压对盾构管片衬砌力学特征与破坏形态的影响模型试验研究

水压力作为一个重要因素,对盾构隧道管片衬砌结构的受力状态及长期安全性具有显著的影响。文中依托广深港客运专线狮子洋盾构隧道工程,采用模型试验的方法,比较分析了0m、30m、60m三种不同水压条件下管片衬砌结构的内力、变形、声发射数据及裂纹产生发展等试验数据信息,探讨水压对盾构隧道管片衬砌结构受力状态及破坏特征的影响规律。研究结果表明：在一定范围内,水压的增加,延长了管片衬砌结构的弹性受力阶段及塑性发展平台,延缓了结构内部出现损伤破坏的时间,提高了衬砌结构的极限载能力。随着水压的增加,管片临界失稳点的最大位移与隧道外半径之比由2.33%增大到2.77%,但是由局部损伤破坏出现到管片衬砌结构整体失稳的过程变得更短,发展速度变得更快,管片的主要破坏形式由以受拉破坏为主变为以压剪破坏为主。     

State taxes and economic growth revisited: have distortions changed?

Our focus is on the changing degree to which individuals and firms respond to state tax policy in the United States. If the economic environment of the past two decades has changed such that firms and individuals have greater mobility, the degree to which they act to avoid higher tax jurisdictions may be enhanced. Alternatively, if tax policies across states have converged, the responsiveness of economic activity to tax policy may have diminished. These potential dynamics may be manifest in, among other ways, a change in the degree to which variation in overall state tax burdens affect state economic growth. Results from a series of regressions using a panel of state-level data for the years 1985 through 2003 indicate that the degree to which higher tax burdens reduce economic growth has substantially diminished. For instance, results indicate that the negative effect of a $1,000 increase in state own-source revenues per capita had on the growth rate of private sector gross state product diminished from approximately negative 1.1 percentage-points in 1985 to virtually zero by 2003. This effect holds whether economic growth is measured as the growth rate of private sector gross state product or private sector employment in a state, whether tax collections are measured in inflation-adjusted per capita terms or as a share of state personal income, and whether we examine state taxes exclusively or combined state and local taxes.     

Clean energy transition in the Turkish power sector: A techno-economic analysis with a high-resolution power expansion model

The Turkish power sector achieved rapid growth after the 1990s in line with economic growth and beyond. However, domestic resources did not support this development and therefore resulted in a high dependency on imported fossil fuels. Furthermore, the governments were slow off the mark in introducing policies for increasing the share of renewable energy. Even late actions of the governments, as well as significant decreases in the cost of wind and especially solar technologies, have recently brought the Turkish power sector into a promising state. A large-scale generation-expansion power-system model (TR-Power) with a high temporal resolution (hours) is developed for the Turkish power generation sector. Several scenarios were analyzed to assess their environmental and economic impacts. The results indicate that a transition to a low-carbon power grid with around half of the electricity demand satisfied by renewable resources over 25 years would be possible, with annual investments of 3.97–6.88 billion in 2019 US$. Moreover, TR-Power indicates that the shadow price of CO₂ emissions in the power sector will be around 17.1 and 33.8 $/per tCO2 by 2042, under 30% and 40% emission reduction targets relative to the reference scenario.     

Toward a method of determining the impact of tourist expenditures on state tax revenues

This paper presents an econometric approach to analysis of the relationship between tourist expenditures and state tax revenues. Following earlier writers, a multiplicative tax production model is employed with number of tourists included as a proxy variable for tourist expenditures. Time-series and cross-section regressions are run for several tourist impacted categories of state tax. Data from Florida are used for the 1960–70 time period.The results indicate that the model performs well using ordinary least squares. Tourist elasticity estimates generated are used to compute hypothetical tax contributions. These appear to be reasonable, though no definitive statements about direct tax exportation can be made. The contribution of the paper is that it provides a beginning step toward econometric quantification of the tourist impact on state economies.The author wishes to thank Jon Silberman, Wayne Talley, and Tony Huggins for their help. Financial assistance was provided by the Old Dominion University Office of Research.     

土地增值税清算的解读

对土地增值税的清算进行了解析,从土地增值税清算对房地产企业的影响、土地增值税清算缘何进展缓慢、土地增值税对于房价的影响三个方面进行了研究,分析了清算土地增值税对于房地产业和房价的影响。     

复杂地质条件下大埋深隧洞衬砌与围岩协同作用#br# 物理模型试验研究

围岩-支护协同作用是地下工程支护结构设计的核心问题,关乎着地下工程建设的成败。为揭示深埋隧洞围岩与支护结构协同作用机理,以滇中引水最大埋深约1512m的香炉山隧洞为研究背景工程,首次开展复杂地质条件下深埋隧洞衬砌与围岩协同作用真三维地质力学模型试验,真实再现隧洞开挖与支护的施工全过程。模型试验研究表明：1）不同地质条件下隧洞围岩的应力释放过程不同,硬岩隧洞围岩应力释放速率先慢后快,软岩隧洞应力释放速率先快后慢;2）不同地质条件下隧洞衬砌与围岩接触压力的分布形式不同,硬岩隧洞最大接触压力位于拱肩,软岩隧洞最大接触压力位于拱顶;3）衬砌与围岩协同作用包括两种应力释放机制、3个施工阶段和4种承载状态;4）不同地质条件下隧洞衬砌施作后围岩和衬砌承担的荷载比例不同,硬岩隧洞围岩平均承担约85%的荷载,衬砌约承担15%的荷载,软岩隧洞围岩平均承担约25%的荷载,衬砌承担约75%的荷载。     

Culture and region revisited

People in different regions of the world live under different cultural and religious orders and derive various practical ethics from them. Some of these moral and religious principles are clearly more favorable for economic development than others. Yet such ethnological differences are regrettably absent from our prevailing theories of regional economic development. In this paper, culture is defined as a system of relatively slow processes of change — known as cultural arenas. A complex interface exists between these slower processes and the relatively faster ones (known as games). In attempting to assess the development prospects of any region, a key point to grasp is that this cultural interface may be self-organizing. Its future trajectory will therefore be uncertain. To the extent that the proposed system of slow processes may be construed as a region's cultural base, they may control the nature and achievable pace of that region's development.An earlier version of this paper was presented at a Conference onThe Economics of the Cities of Art, held in Venice from 13–15 May 1991.     

考虑土拱效应的挡土墙空间土压力研究

 研究表明土拱效应是影响挡土墙土压力分布的一个重要因素,但目前关于空间条件下考虑土拱效应的挡土墙土压力研究还很少。通过将土拱效应原理引入顾慰慈等建立的空间土压力计算模型建立了考虑土拱效应的空间土压力计算模型,并将该模型划分为I、II、III、IV四个区域,通过在各个区域内取水平微分单元体,建立各微分单元体的水平和竖向静力平衡方程,推导出了各区相应的挡土墙空间主动土压力计算公式,该公式可以计算出墙背任意位置的主动土压力;并提出了空间土压力合力及其合力作用点的计算方法。通过算例计算可以直观的看出挡土墙后主动土压力的空间分布,由此可以看出,当空间效应存在时考虑土拱效应的挡土墙主动土压力沿墙长的分布与平面应变条件时有很大的不同,此时挡土墙两端附近区域的主动土压力远小于平面应变条件下计算出的主动土压力,同时可以看出考虑空间效应的挡土墙主动土压力合力作用点要比平面应变条件下的位置要高,挡土墙长高比B/H越小空间效应对主动土压力沿墙长的分布和主动土压力合力作用点位置的影响越大。     

Land development timing: Effects of uncertainty in income and tax policy

This paper investigates several sources of uncertainty and their effects on the optimal timing of land development. The method of Meyer and Ormiston (1983, 1985) for strong increases in risk and their comparative statics, is applied. There are three basic results. First, a strong increase in risk in the pre-development income stream speeds the development process, regardless of whether the random effect is incorporated in an additive or multiplicative form in the model. Second, strong increases in risk in pre-development property tax rates delay development. Finally, a strong increase in risk in the post-development income stream results in a slower development process.An earlier version of this paper was presented at the 37th North American Regional Science Meetings, Boston, Massachusetts, November 1990.     

LNG卫星站冷能利用项目开发

LNG冷能用于冷库工艺流程,略微增加了原有LNG气化系统的压力降,不影响整体气化量和天然气压力控制。该项目总投资90．88×10^4元,年均销售收入74．80×10^4元／年,内部税后收益率48．07％,具有较高的赢利空间。该工艺的LNG冷能利用率可达87．8％,其冷火用利用率达26．8％,尚有较大利用空间。远期规划建立冷媒循环系统来回收利用LNG冷能,用于废旧橡胶低温粉碎、二氧化碳液化和干冰制备、中小型低温冷库等中试项目,建成LNG冷能高效利用技术示范基地。